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In the absence of signal, the background white noise may appear quite loud. For ease of
listening, the squelch control should be rotated clockwise until he background noise just
disappears, this should be carried out while no signal is present. The point where the
background noise is cancelled is known as threshold point. Do not advance the squelch
control more than necessary or the receiver will appear to be desensitized and weaker
signals will be missed.
WFM – Wide Band Frequency Modulation – used by VHF and UHF broadcast stations as
excellent audio quality is available due to the relatively wide frequency bandwidth
employed.
Used only for local services such as VHF band stereo (received as mono on the AR-ONE)
and UHF TV sound channels.
LSB – Lower Side Band – is form of SSB (Single Side Band). LSB tends not to be used
commercially but is extensively used by Radio Amateurs on frequencies below 10 MHz.
This assists the separation of Commercial and Amateur users on traditionally shared bands
and prevents them from speaking to each other.
SSB is a very efficient method of transmission as the unwanted second sideband and
carrier
have been removed. This allows the full transmitter power to be employed in carrying
useful information within the wanted sideband. As a result, greater distances are possible
on
SSB and a smaller frequency bandwidth is required than most other modes.
USB – Upper Side Band – The same comments apply as for LSB. By convention, Radio
Amateurs also use USB above 10 MHz.
CW -
Continuous Wave – Often referred as Carrier Wave or Morse Code. Commonly
used
on the short wave bands by radio amateurs toward the lower end of each band allocation.
Some commercial use is still made by shipping etc although its use is being phased out
due
to the introduction of automated stations.
2-5-1 Auto-mode selection
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